1. Field of the Invention
This invention relates to a one-way clutch and an auxiliary machine using the same. This one-way clutch is capable of accommodating a pulley to be mounted in the auxiliary machine driven by, for example, a crank shaft of an automobile engine through a belt. As the auxiliary machine, there are a compressor, a water pump, an alternator, a cooling fan and a crank pulley in an air conditioner of an automobile.
2. Description of the Related Art
Generally, a one-way clutch comprises an inner wheel, an outer wheel, a holding device, and a plurality of coil springs. The holding device has a plurality of pockets penetrating from inside to outside in a diameter direction and having a rectangular shape as viewed in plan, the pockets being provided at several positions on a circumference of the holding device. With the holding device sandwiched between the inner wheel and outer wheel, the roller and coil spring are accommodated in a space limited by an inner wall of each pocket, an outer circumference of the inner wheel and an inner circumference of the outer wheel. The coil spring is accommodated in a condition in which it is compressed in a circumferential direction and urges the roller to a locking side (to a narrow side of the aforementioned space) by its expanding restoration force. The coil spring has a general shape that it is wound in a cylindrical shape to obtain its expanding restoration force, and in the space within the pocket, the coil spring is accommodated in a state in which an end portion in the expanding direction is in contact with the intermediate portion in the axial direction.
The accommodated coil spring is likely to be distorted in an unstable shape like a "V" shape as viewed from the top when it urges the roller to the locking side or free side (to a wider side of the aforementioned space) with relative rotating motion between the inner wheel and outer wheel. The distorted coil spring is not capable of providing the roller with an appropriate urging force and further may skew the roller. If any one of the rollers is skewed, an excessive load is applied to end portions of the roller thereby likely causing eccentric abrasion or peeling. Further, the locking and free operations of the roller become unstable, thereby the reliability of the operation of the one-way clutch being reduced.